Plastic sugery done to remove moles from cheeks before 6 months. Dark stitches are visible now also. What to do? How long they will remain?

Have it checked . After 6 months, a majority of the dissolvable sutures are gone, so these could be buried permanent sutures. If the stitches were originally removed and a small part of the stitches were left in, they can be dug out and removed by the doctor. Have this evaluated, especially since it has been 6 months.
Dark Stitches. If you are seeing stitches six months after surgery, go back to see your surgeon. Anything visible should be removed.